Removable stitch pattern template means for sewing machines



April 29, 1969 L. BONO 3,440,980

REMOVABLE STITCH PATTERN TEMPLATE MEANS FOR SEWING MACHINES Filed Jan. 12. 1967 Sheet of 2 i gu April 29, 1969 1.. BONO 3,440,980

REMOVABLE STITCH PATTERN TEMPLATE MEANS FOR SEWING MACHINES Filed Jan. 12, 1967 Sheet 3 of 2 1H FIG.2

44 24 s51 s35 59 52 26m 2s 19 15 28,-29 33 as 3? s4 4e m g a '34 iil 1 A6 58 22 21 45 as United States Patent Office 3,440,980 REMOVABLE STITCH PATTERN TEMPLATE MEANS FOR SEWING MACHINES Luigi Bono, Pavia,-':Italy, assiguor to Necchi Societa er Azioni, Pavia, Italy Filed Jan. 12, 1967, Ser. No. 608,814 Claims priority, applizcgeigl Italy, Jan. 12, 1966,

Int. Cl. D]! 23/00; D050 3/02, 7/04 US. Cl. 112-2 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to sewing machines where in a fabric holding frame carries a fabric beneath a sewing needle to effect a predetermined stitch pattern thereon, said frame being guided to move in conformity with the peripheral contour of fixed magnetic plates, the invention being directed to the provision of pattern template means which is replaceable and interchangeable easily and without the necessity of replacing the entire magnetic plates.

As is known, pattern templates usually consist of identical, parallelly spaced magnetic plates between which is mounted an electromagnetic means which creates a magnetic flux flowing along a closed path defined by said plates, by the electromagnetic means therebetween, and by a rod extending across the profiled ends of the spaced plates. Said rod is connected to the fabric holding frame and is adapted to roll along the spaced peripheral ends of said plates thereby guiding said frame to move in conformity with the contour of said ends, said rod being magnetically held against said ends by virtue of the fact that said rod closes the magnetic circuit between the spaced apart plates. In such known templates, therefore, the pattern defining means simply constitutes the end wall of the magnetic plates between which the electromagnetic means is mounted, and in order to change the sewing pattern the said magnetic plates in their entirely, including the electromagnetic means therebetween, must be changed since the pattern defining end walls are an integral part of the magnetic plates. Such a condition, obviously entails a considerable amount of time and difiiculty and consequent expense. Examples of such prior known template means are found in Italian Patents 685,366, and 678,248.

The present invention, on the other hand, obviates the aforementioned disadvantages through the provision of template means which are separably attachable to magnetic plates. Specifically, the template means comprises relatively narrow plates which are attachable along the end walls of the magnetic plates. The template means, therefore, forms a planar extension of the magnetic plates without being an integral, inseparable part thereof. Consequently, the pattern defining template means can be replaced without having to replace the plates made of magnetic material, the electromagnetic means therebetween, and related electrical circuitry elements, all of which constitute more expensive elements relative to the template means.

3,440,980 Patented Apr. 29, 1969 It is an object of the present invention, to provide a pattern defining means which is replaceable without having to replace the entire magnetic plates.

It is a corollary. object to provide a pattern defining means which is replaceable more easily, in less time, and with less cost than heretofore.

It is a further object to provide a variety of pattern defining means for a sewing machine which occupy less storage space, which are easier and less costly to transport, and which are less costly to renew than heretoore.

Other objects are those which are inherent and obvious in the disclosed invention which will now be described in detail with reference to a preferred embodiment thereof as illustrated in the accompanying drawings, wherein:

FIGURE 1 is a pictorial view of an assembled sewing machine which includes a template means according to this invention;

FIGURE 2 is a plan view of only the magnetic plate means and immediately adjacent parts;

FIGURE 3 is an end view taken along line III--III of FIGURE 2; and,

FIGURE 4 is a perspective view of only the template means according to this invention.

Referring to FIGURE 1, a sewing machine 1, which is mounted on table 2, is driven by motor 3 through a not shown drive transmission means in order to sew a stitch pattern in cloth 4. Said cloth is firmly spread and clamped on frame 6 which carries the cloth past the sewing needle 5, said frame moving in accordance with the desired stitching pattern which is to be sewn into said cloth. The frame 6 is fixedly carried at the upper end of arm 7 which extends downwardly through slot 8 in table 2, said arm 7 being rigid and movable with two guides which are movable perpendicularly relative to each other. The attachment of arm 7 to said guides is not shown but is well known and is disclosed in detail in Italian Patent 678,248.

The assembly of arm 7 and the two guides is, in turn, driven by means of rotatable rod 9 (FIGURES 2 and 3) which magnetically adheres to and rolls without sliding along the profiled end walls 48 of the spaced apart templates. The cloth holding frame 6, therefore, moves relative to needle 5 in accordance with the contour of said end walls.

With reference to FIGURES l and 2, the table structure also comprises spaced cross members 10 and 11 perpendicularly to which are fixedly attached the parallel guide bars 12 and 13 which serve as axial sliding supports for not shown sleeves which, in turn, carry the support plates 14, 15, 16. A threaded shaft 18 extends parallelly between guide bars 12 and 13 and through cross member 11 in which it is rotatably journalled but fixed against axial displacement. A hand actuable wheel 17 is attached at one end of shaft 18 for the purpose of rotating said shaft.

The middle portion and the end portion, adjacent to cross member 10, of shaft 18 are threaded, the thread of the middle portion having a larger diameter and half the pitch of the end portion thread. The respective middle and end portion threads of shaft 18 are engaged in correspondingly threaded sleeves which are attached fixedly to supporting plates 15 and 16. Rotation of wheel 17 and through it rotation of shaft 18, therefore, results in simultaneous axial movement in the same direction of plates 15 and 16, plate 16 moving twice the distance that plate 15 moves, while plate 14 remains stationary. This means that end plates 14 and 16 are always symmetrically main- 3 tained, that is: equally spaced, relative to middle plate 15.

Bracket 20 is fixedly attached to middle plate by means of machine bolts 19, said bracket including spaced upper and lower arms 21 to which are fastened two small blocks 22 of magnetic material. Blocks 22 are vertically spaced apart and superposed relative to each other (FIG- URES 2 and 3).

The magnetic plate means of this invention comprises a middle sector 23 consisting of bracket and the small blocks 22, and side sectors 24 and 25 which are respectively mounted on support plates 14 and 16. The side sectors 24 and 25 are each formed by a pair of spaced, parallel plates 26, 27 and 28, 29, respectively, said plates being of magnetic material and between which are mounted electromagnets 30 and 31, respectively. Bolts 32 and 33, of non-magnetic material, serve to clamp the respective pairs of plates to the electromagnets therebetween.

The side sectors 24 and 25 include spacer support bosses 34 on their lower faces resting against the upper faces of support plates 14 and 16. Two bosses 34 on each sector are recessed in order to receive therein alignment pins 35 which are mounted on said plates 14 and 16. A machine bolt 36 fastens each sector 24 and 25 on its respective plate 14 and 16.

The pairs of plates which comprise the side sectors 24 and 25 include facing laterally extending reduced width portions 37 which are slidably received between the upper and lower sides of bracket 20.

The pattern defining template means of this invention comprises respective sectors 38 and 39 each respectively comprising parallel spaced fiat rims 40, 41 and 42, 43, the respective pairs of rims being spacedly fixed relative to each other by spacers 44 which are of non-magnetic material. The template sectors 38 and 39 are each provided with positioning pins 45 for engagement in notches 46 in the magnetic plate sectors 24 and 25, whereby the exact positioning of the template sectors relative to the magnetic plate sectors is assured.

The template sectors 38 and 39 are each clamped between the plates 26, 27 and 28, 29, respectively, by means of clamping bolts 47 also of non-magnetic material which connect the respective magnetic plates together.

The exposed end walls 48 of the template sector rims 40 to 43, together with the exposed end walls 49 of the small blocks 22 constitute the pattern defining profile along which rod 9 rolls during the operation of the sewing machine.

The electromagnet 30 creates a magnetic fiux which follows a path defined by the magnetic plate 26, the template rim 40, the rod 9, the template rim 41, the magnetic plate 27, and the electromagnet itself 30. An analogous path is defined by the respective sectors 25 and 39 together with magnet 31. Since rod 9 constitutes an essential link in the formation of a closed flux circuit, it is held by magnetic attraction within said circuit and, therefore, against said end walls 48 and 49. Said rod 9 is rotatably driven by the machine motor and thereby rolls along said end walls 48 and 49 without, however, sliding therealong. In this regard, it should be noted that the spaced magnetic plates as well as the spaced rims are magnetically insulated from each other so that the magnetic flux generated by magnets 30 and 31 can only flow along the respective plates and their associated rims with the follower rod 9 serving as a connecting link for said flux between the spaced apart rims. The electromagnets are so arranged that the flux is directed in opposite directions in the upper and lower plates and rims.

When it is desired to change the stitch pattern, it is only necessary to loosen the bolts 47 to remove either or both of template sectors 38 and 39, and to substitute the desired other sector or sectors. Previously, on the other hand, it was necessary to remove, for example, the entire assembly comprising magnetic plates 26 and 27 and the magnet 30.

Additionally, it was necessary to disconnect said magnet 30 from its source of electrical energy and to remove vari ous electrical control means. The previous procedure obviously entailed a considerable amount of time and skill. Furthermore, it necessitated the availability of a plurality of relatvely expensive and voluminous template assemblies since each assembly consisted of the entire magnetic plates as well as the electromagnets therebetween. According to the present invention, on the other hand, not only is the time, difficulty, and cost of pattern changes reduced, but also the problems in transporting and storing substitute pattern templates are greatly reduced.

In the changing of a stitching pattern, it generally is not necessary to change the middle sector 23 since in practice the pattern changes occur only in the side portions of the pattern whih correspond to the template sectors 38 and 39.

What is claimed is:

1. A pattern defining means for a sewing machine wherein a cloth holding frame is moved relative to the sewing needle by means of a rotatable follower which rolls along a pattern defining surface, comprising: a pair of parallelly spaced plates of magnetic material, an electromagnetic means between said plates, a template means comprising a pair of parallelly spaced rims also formed of magnetic material, means removably attaching said template means to said plates in a manner whereby each of said rims form a planar extension of respective ones of said plates, a peripheral end wall of said rims constituting said pattern defining surface, each of said plates with each respectively associated rim forming spaced apart legs of a circuit for magnetic flux generated by said electromagnetic means, the distance between said rims constituting an opening in said circuit.

2. The pattern defining means of claim 1, said template means being received between said plates with said rims extending outwardly of the peripheral end walls of said plates.

3. The pattern defining means of claim 2, including releasable clamping means for urging said plates towards each other, said template means being thereby clamped between said plates with respective surface portions of said rims being in face-to-face contact against respective surface portions of said plates.

4. The pattern defining means of claim 3, each of said rims extending in respective planes between said plates.

5. A sewing machine comprising a sewing needle and a fabric holding frame adapted to move in conformity to a desired stitching pattern relative to said needle, a pattern defining means for guiding the movements of said frame, said means comprising a magnetic flux generating means, a template means defining a portion of a circuit for said flux, a follower attached to said frame and movable along an end wall of said template means, said follower constituting another portion of said flux circuit, means removably attaching said template means to said flux generating means whereby replacement of said template means may be effected without removal or replacement of said fiux generating means relative to said machine.

6. The sewing machine of claim 5, wherein said flux generating means comprises a pair of parallelly spaced plates of magnetic material and an electromagnetic means arranged to generate a magnetic flux flowing in respective opposite directions in respective ones of said plates, said template means comprising a pair of spaced rims means attaching said spaced rims to said plates so as to constitute spaced planar extensions of each of said plates, said follower extending transversely to the planes of said plates and of said rims and bridging the distance between said rims whereby said follower constitutes a connecting link for said flux between said rims.

7. The sewing machine of claim 6, said template means comprising an interconnected unitary assembly of 5 6 said rims whereby said template means is unitarily re- FOREIGN PATENTS placeable relative to said plates. 1,376,273 9 1964 France References Cited JAMES R. BOLER, Primary Examiner.

UNITED STATES PATENTS 5 S X 3,034,545 5/1962 Vesely s2 14 C1 3,216,380 11/1965 Bono 112102 XR 

